One ml of 1 M HCl was added to 50 mg
of a sample in an airtight stoppered vial and heated for 1 h in a
glycerol bath at 80 C under constant agitation at 10g. The mixture
was then cooled to room temperature and centrifuged at
10,621g for 5 min and 0.250 ml of the supernatant was diluted
with 1 ml of distilled water